In general, conventional air conditioning systems utilize engine bleed air to cool, heat, pressurize, and provide fresh air to occupants in an aircraft cabin. Every lb/min of bleed air used to ventilate the aircraft cabin is a penalty to the aircraft performance throughout an operating envelope of the aircraft. Minimum required fresh air flow rates per occupant are set by regulation authorities and must be met. Conventional air conditioning systems fail to properly strike a balance between reducing bleed air consumption while still meeting fresh air flow requirements to reduce fuel burn and aircraft operational costs.